A compressor that compresses a fluid, or a pump generally has a structure of a rotary machine including a rotation body therein.
Generally, such a rotary machine includes an impeller as a rotation body, wherein the impeller is configured to increase the pressure of a fluid by transferring rotary motion energy to the fluid. Accordingly, the impeller includes a plurality of blades for helping the flow of the fluid and transferring energy to the fluid.
A shroud is disposed outside the impeller to form a flow path of the fluid along with the blades.
Generally, since the efficiency of the compressor increases as intervals between the blades and the shroud decrease, the shroud has been recently manufactured by being combined with the impeller to thereby increase the efficiency of the compressor.